Prehospital Hypoxia Affects Outcome in Patients With Traumatic Brain Injury: A Prospective Multicenter Study: Chi JH, Knudson MM, Vassar MJ, et al. J Trauma 2006;61:1134–41

Abstract

This prospective, multicenter cohort study identified patients with suspected head injury who underwent helicopter transport to a level I trauma center and examined the association of secondary insults (hypoxia – SpO2 < 92% and hypotension; systolic blood pressure < 90 mm Hg) with mortality and disability at discharge. Of 319 patients transferred to level I trauma centers in four different cities (Dayton, OH; Philadelphia, PA; Davis and Fresno, CA) with suspected brain injury over a 2-year period, 150 had acute traumatic brain injury identified by computed tomography (CT) scan, operative findings or autopsy, or had a head Abbreviated Injury Scale (AIS) score of at least 3 or a Glasgow Coma Scale (GCS) score of <12 within the first 24 hours of admission, and were included in this study. Bivariate analyses were performed to determine the association of the presence, duration, and frequency of hypotension and hypoxia with dependent variables. This information was used to identify covariates for multivariate logistic regression analysis. Bivariate analyses found that hypoxia, older age, lower GCS score, Marshall score, head AIS score, and multiple trauma had a significant effect on mortality, whereas hypotension, Injury Severity Scale (ISS) score, need for intracranial or extracranial surgery and lung injury were not significant predictors of mortality. In multivariate analyses, hypoxia, age > 65 years, and GCS score of ≤ 8 were independent predictors of mortality, whereas hypotension was not. Secondary insults were associated with an increased Disability Rating Scale (DRS) of >15 and increased length of hospital stay. The authors conclude that prehospital insults, particularly hypoxia, have a significant effect on mortality and disability in patients with traumatic brain injury. They stress the importance of further studies to examine the relationship between traumatic brain injury and pulmonary dysfunction.